Process of cracking hydrocarbon oil



Nov. 17, 1931. J. D. sEGUY 1,832,819

PRocEss oF CRAGKING HYDRocARBoN on.

Original Filed Dec. 27, 1927 Patented Nov. 17, 1931 UNITED STATES PATENT OFFICE JEAN DELATTRE SEGUY, O1* CHICAGO, ILLINOIS, ASSIGNOR T0 UNIVERSAL OIL PROD- AUCTS COMPANY. OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA PROCESS OF CRACKING HYDROCARBON OIL Application filed December 27, 1927, Serial No. 242,555. Renewed October 1, 1930.

accompanying drawing, which is a diagrammatic view of an apparatus suitable forearrying out the invention, but. 1t 1s understood that this drawing is diagrammatic and not to scale.

Referring to the drawing, 1 designates a furnace on Which is mounted a heating or cracking coil 2. lThe coil is connected by transfer line 3 having throttle valve 4 to the insulated reaction chamber 5. From the top of the' reaction chamber 5, the vapors may pass through vapor line 6, having throttle ,valve 7 into the-lower side of the dephlegmator 8. The vapors which are not condensed in the dephlegmator pass out through vapor yline 9 to condenser 10 and thence to receiver 11. This receiver 11 has gas release control valve 12 and liquid discharge control valve 13.

The residue is drawn out through the lower part of the chamber by draw-olf pipe 14 connected to branch 15 leading to the flash chamber 16. A pressure reducing valve 17 is interposed in the line 15. The line 14 has a throttle valve 18.

The residue from the flash chamber 16 is drawn out through pipe 19, having throttle valve 20. The vapors from the flash chamber 16 pass out through pipe 21, having throttle valve 22a, into a series of serially connected vapor phase crack- .ing chambers 22. I have shown two in the drawing, but more than two can be used, if desired. Chambers 22 have residue draw-offs Y 23 controlled with throttle valve 24. From the last chamber 22 the vapors pass through pipe 25, having throttle valve 26, into the side of dephlegmator 27. From the top of this dephlegmator, the uncondensed vapors. and gases pass through line 28 and condenser coil 29 to receiver 30. This receiver 30 has gas control valve 31 and distillate control valve 32.

To the dephlegmator 27 may be directly fed through pipe 33 having control valve 34, the raw charging stock, or4 if desired, the temperature may betcontrolled by passing the raw charging stock through the closed coil 35, having valves 36 and 37 and in the latter case, the preheated oil may be fed to the feed pump 38 and main inlet line 39, leading to the coil 2. The reflux condensate and the preheated raw oil, if the latter is fed directly into the dephlegmator 27, pass through line 40 and pump 41 and line 42 to the inlet Jfeed pipe 39.

The reflux condensate from the primary dephlegmator 8 may be'fed to the line 21 through the pipe 43, having control valve 44, or the reflux from the main dephlegmator 8 may be fed through the line 4 5, having control valve 46 into the line 15 beyond the reducing valve 17. Also, if desired, the dephlegmator 8, condenser 10 and receiver 11 may be cut out of the system and the vapors from the chamber 5 passto the line 21 through branch 47 having control valve 48.

' The arrangement is such that in one method of carrying out the invention, the gasoline vapors and lighter gases will be separated in the dephlegmator 8 from the heavier reflux and then this reflux returned through line 43 to the line 21, the valve 44 in such case being used as a pressure reducing valve and the reflux ashed into the line 21 at the same pressure-as is on the chamber 16. In such case, the valve 7 will be opened and the valves 48 and 46 closed.

Another method in which the invention may be -operated would be to close the valves 44 and 48 and use the valve 46 as a pressure reducing valve, whereby the reiux condensate will pass to the chamber 16. This might be desirable Where the reflux condensate to Hash is particularly heavy, and its heavier fractions will be removed through the line 19 with the residue. Another method of operating the invention would be to close the valves 7, 44 and 46 and pass all of the vapors through line 47, using the valve 48 as a pressure reducing valve.

I have provided means for effectively heating the vapors in chambers 22 by passing the Hue gases from furnace 1 through the Hue 49 in which is interposed a fan 50, this flue lead- A ing to the first chamber 22. The arrangement is such that the Hue gases come into direct contact with the vapors and superheat them. It is, of course, desirable to control and, in some cases, Within relatively narrow limits, the temperature in the chamber 22. To this end, I am interposing a cooling coil 51, having valves 52, in the Hue 49 to cool the gases if too hot. If the gases are not hot enough, I provide an auxiliary heater 53, having Hue 54 connected, as shown at 55, to the Hue 49. The arrangement of this auxiliary heater is such that the gases of combustion may enter Hue 49 under the pressure of the balance of the system.

In one method of carrying out the invention, incondensible gas and extraneous gas may be also introduced into the chambers 22 by means of the line 56, having valves 57. Preferably, this gas may be pre-heated by passing it through the heating coil 58, located in the heater 53 and the gas, introduced under suHicient pressure to enter the chambers 22, may be either inert gas, such as nitrogen or the like, 0r a hydrogenating gas, such as hydrogen. It may be ca rbon monoxide or carbon dioxide, or steam. The use of such incondensible gases is claimed in my copending application Serial No. 242,556 of even date.

Another method of operating the invention may be to close the damper 59 in the Hue 49 and open the damper 60 in the branch 61. In such case, the heated gas introduced through the pipe 56 may be the only means for superheating the vapors in the chambers 22.

In carrying out either of the above two last mentioned methods, the chambers 22 may be also externally heated through the furnaces 62.

Another method of carrying out the invention may be to put a catalyst, such as iron oxide or other suitable matter in the chamber 5, or the chambers 22, or in both of them. In all of the various methods above referred to, the oil may be subjected to a pressure of say 200 lbs. or more in the coil 2 and the chamber 5. The pressure in the chamber 16 and the dephlegmator 8 and the chambers 22 and the dephlegmator 27 and its associated parts may be substantially lower than the pressure in the coil-say from 100 lbs. down to atmosheric pressure. `Another manner of carrymg out each of the foregoing methods Would be to have a pressure of say 350 lbs. on the coil 2 and chamber 5, a pressure of say 100 lbs. on the chamber 16 and dephlegmator 8 (in case the latter is not cut out of the system) While by regulating the reducing valve 63 on line 21 from 25 lbs. say to atmospheric pressure lmay bemaintained onthe chambers last mentioned case, a vacuum may be maintained in the chambers 22 by connecting a suitable vacuum pump, not shown, to the receiver 30.

In carrying out any of the methods above described, the degree of cracking in the liquid-vapor phase part of the system, to-Wit, in the coil 2 and chamber 5, may be independently controlled relative to the degree of cracking in the vapor phase cracking chambers 22.

Transfer temperature in the coil 2 may be say 850 F., more or less, while the temperature in the chambers 22 may be 1000o F. more or less.

By subjecting the vapors to vapor phase cracking in the chambers 22 with the gases therein contained in the manner heretofore described, gasoline containing relatively large percentages of anti-knock compounds may be formed. Also, other compounds may be formed, such as oxygenated compounds.

In carrying out any method of the above described process, it is desirable to have substantially complete combustion of the Hue gases before they enter the chambers 22 in order to avoid combustion of the hydrocarbon vapors.

I claim as my invention:

1. In a process for cracking hydrocarbon oil consisting in subjecting the oil to a liquidvapor phase cracking pressure reaction, separating the oil into vapors and heavier residue', then subjecting the vapors to a vapor phase cracking reaction and simultaneously introducing into said vapors spent combustion gases and regulating the temperature of said combustion gases Within relatively narrow limits, the improvement which comprises subjecting the heavier residue to Hash distillation, and subjecting the vapors therefrom to vapor phase cracking.

2. A process for cracking hydrocarbon oil consisting in heating the oil in a crackin coil located in a furnace, passing the heate oil to an enlarged expansion chamber Where vaporization takes place, removing the vapors and subjecting more or less of them to a vapor phase cracking reaction, removing the residue and subjecting it to Hash distillation under reduced pressure, subjecting the Hashed vapors to said vapor phase cracking reaction and introducing the spent combustion gases from said furnace under regulated temperature into direct contact with the vapors being subjected to said vapor phase cracking reaction.

3. A process for cracking hydrocarbon oil consisting in heating the oil to a cracking tempera-ture under superatmspheric pressure, passing the heated oil to an enlarged zone Where vaporization takes place, separating the vapors from the residue, subjecting the residue to Hash distillation to separate 65 22 and dephlegmator 27, or if desired, inthe: furthery vapors therefrom, and s'ubjectmg all of the vapors evolved in the process to vapor phase cracking, and introducingspent combustion gases under regulated temperature into direct contact with the vapors being subjected to vapor phase cracking.

4. A hydrocarbon oil cracking process which comprises subjecting the oil to cracking conditions of temperature and pressure, separating evolved vapors from unvaporizedV oil, iash distilling said unvaporized oil by lowering the pressure thereon, vapor phase cracking resultant flashed vapors in direct contact with spent combustion gases in a manne-r to convert the flashed vapors into gasoline, and condensing the resultant gaso-l line vapors.

5. A hydrocarbon oil cracking process which comprises subjecting the oil to cracking conditions of temperature and pressure, separating evolved vapors from unvaporized oil, Hash distilling said unvaporized oil by* lowering the pressure thereon, and vapor phase cracking resultant ashed vapors admixed with at least a portion of said evolved vapors in direct contact with tion gases.

6. A process as defined in claim 4 further characterized in that said evolved vapors are dephlegmated to form reflux condensate and such condensate combined with the flashed vapors undergoing vapor phase cracking.

JEAN DELATTRE SEGUY.

spent combus- 

